Effects of epsilon-pyridoxyllysine and related compounds on liver and brain pyridoxal kinase and liver pyridoxamine (pyridoxine) 5'-phosphate oxidase.

The in uitm metabolic effects of e-pyridoxyllysine, shown to be a degradation product of vitamin Be in foods, and several of its derivatives have been examined using partially purified pyridoxal kinase (EC 2.7.1.35)from bovine brain and rat liver and rabbit liver pyridoxamine (pyridoxine) 5"phosphate oxidase (EC 1.4.3.5).a-Pyridoxyllysine competitively inhibits pyridoxal kinase of both brain and liver tissue, with inhibition efTiciency ratios (K,,, for p~doxal/Ki) of 5.0 and 0.6, respectively.The 5'-phosphorylation of epyridoxyllysine by brain and liver pyridoxal kinase was demonstrated using high performance liquid chromatography, showing K,,, values of 24 and 206 p ~, respec-